SAO PAULO, Sept 9 (Reuters) - Small gold miners that have been working on illegal pits in the Amazon rainforest blocked an important road for grains transportation in Brazil's Para state on Monday, protesting a crackdown by the government, police said.

The miners, mostly habitants of Moraes Almeida, a district in the Itaituba municipality that is at the center of an environmental crisis due to widespread fires in the forests surrounding it, blocked the BR-163 federal road. The road is used by commodities traders to transport soybeans and corn from Mato Grosso farms to a port at the Tapajós river in Para.

"There was a total obstruction on the road at km 411, leading to traffic congestion in both ways," said the federal police, answering a request for comment from Reuters.

The police said miners were protesting recent raids from Brazil's environmental defense teams that led to seizure and destruction of equipment found in protected areas inside the forests, where mining activity was going on.

According to the police, miners are asking the government to stop those raids and halt destruction of equipment. They have also asked the government to legalize some mining areas in the region that would enable small miners to work.

Corn shipments from the Tapajós river port at Itaituba are in full swing, since Mato Grosso recently finished harvesting its major crop of the cereal. Brazil is exporting a record amount of corn this year, after a bumper harvest.

Illegal mining is one of the activities green groups blame for the destruction of the rainforest. Illegal logging and some clearing for agriculture and livestock are other actions seen as drivers of deforestation.

Brazil President Jair Bolsonaro had promised to legalize some areas for small and large-scale mining activities in northern Brazil. His remarks in the past could have boosted illegal mining in the Amazon.

Police said it was not clear when protests would end. It said some vehicles were allowed to cross the protest from time to time. (Reporting by Marcelo Teixeira in Sao Paulo Editing by Matthew Lewis)